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6th Grade Science / Lesson 2 - Properties of Minerals

Properties of Minerals
What will we be learning today?


  • In this lesson, we are going to learn about the properties of minerals.

  • We will begin today's lesson, by listing the properties of minerals and explain each property.


Properties of Minerals are:


  • Luster

  • Color

  • Texture

  • Hardness

  • Streak

  • Cleavage

  • Fracture

  • Density


  • Luster is the way a mineral reflects light. There are two main classes: the metallic minerals and the nonmetallic minerals. A metallic mineral will have a shine to it when light strikes it. (metallic, pearly, glassy, silky and greasy) A nonmetallic luster, or dull appearance, will occur in nonmetallic minerals.

  • Color is the general appearance of the mineral but is the least reliable property to help identify a mineral.

  • Texture is the size of the grain or crystals in the rock. The grains may be coarse, fine, or nonexistent.


  • Hardness is measured by seeing how easy it is to scratch a mineral. For example, talc, the softest mineral known, can be scratched with a fingernail. Diamond, the hardest mineral, can scratch all the other minerals but cannot be scratched by them.

  • In 1822, a German mineralogists, Friedrich Mohs, developed a ten-point scale of hardness. The same scale is used today.

  • Here is the Mohs hardness scale:

    1. Talc            Least Hard
    2. Gypsum
    3. Calcite
    4. Fluorite
    5. Apatite
    6. Feldspar
    7. Quartz
    8. Topaz
    9. Corundum
    10. Diamond      Most Hard


    • Streak is the color of the streak obtained by rubbing a mineral across a hard, rough surface. The color of the streak made by a mineral is often different from the color of the mineral itself because of contact with air and water.

    • Cleavage is how a mineral breaks along flat surfaces in a very definite way.

    • Fracture is how a mineral looks when it breaks apart in an unevenly or irregular way.


    • Density is the measure of how much matter there is in a given amount of space.

    • Density is a ratio of an object's mass to its volume.

      Example:

    • Pick up a golf ball and ping pong ball, which will feel heavier ?

    • The balls are the same size, the golf ball feels heavier because it's denser.